Curable silicone compositions that contain a resin-like organopolysiloxane are known. For example, Japanese Unexamined Patent Application Publication (hereinafter referred to as “Kokai”) H07-53872 discloses a curable silicone composition that contains a diorganopolysiloxane having both molecular terminals capped with vinyl groups, a resin-like organopolysiloxane that contains alkenyl groups, an organohydrogenpolysiloxane, and a platinum-type catalyst. Kokai 2000-198930 discloses a curable silicone composition that contains a diorganopolysiloxane having at least two alkenyl groups in one molecule, a resin-like organopolysiloxane that contains alkenyl groups, an organohydrogenpolysiloxane, and a platinum-type catalyst. Furthermore, Kokai 2001-2922 discloses a curable silicone composition that contains a diorganopolysiloxane having at least two alkenyl groups in one molecule, a resin-like organopolysiloxane that contains alkenyl groups, an organohydrogenpolysiloxane, and a platinum-type catalyst.
When the amount of resin-like organopolysiloxanes contained in such curable silicone compositions is increased, it becomes possible to obtain a cured silicone body with appropriate hardness, reduced surface tackiness, and sufficient strength. However, the compositions themselves are extremely viscous and therefore have low flowability and filling ability.
It is an object of the present invention to provide a curable silicone composition that possesses excellent flowability and filling ability and that can be prepared without exhibiting an extreme viscosity even if the composition contains resin-like organopolysiloxanes required to form a cured silicone body of appropriate strength and hardness.